Condensation pump



June 27, 1933. c. T. KNIPP CONDENSATION PUMP Filed Oct. 13, 1930.

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Patented June 27, 1933 UHTED STATES @Fiiiijii 'l. KNIFE OF URBANA,

CHARLES TUBING 00., or onrcaeo,

connnnsa'rron rmvxr Application filed October 13, 1930. Serial No.488,312.

The present invention relates to a condensation pump and hasparticularly to do with a method and means of cooling employed thereinand in the arrangement and structure of the several elements thereof.

The eifectiveness of a vapor pump is due in the greatest measure to theefficiency of its condensing element. It was with this idea in mind thatthe present construction 19 was developed. l

The primary object of the present invention is an improved condensingelement. The secondary object of the inventionis an improved arrangementof parts for the purpose of increasing the efliciency of the con(lensing element. Another object of the invention is an improved designfor a condensation pump and its elements.

Other and additional objects of the invention include novelties in thearrangement of the several elements of'the pump and in the details ofsuch parts.

These objects, and such other objects as hereinafter appear, areobtained by the novel construction, unique arrangement and improvedcombination of elements in the two forms of invention herein illustratedand described thedrawing appended hereto and hereby made a part of thisspecification, illusirating the present invention as applied to a singlestage condensation pump and also as applied to a double stagecondensation pump.

In the drawing- Figure 1 is a longitudinal section through a singlestage pump embodying the subject matter of the present invention;

Figure 2 is a similar View of a double stage pump also embodying theinvention.

Like reference characters are used to designate similar parts in thedrawing and in the description of the invention hereinafter given. g

Condensation pumps. in order to provide the vacuum, for which they aredesigned, must always be used in conjunction with primary or as they arecalled, backing pumps. Such backing pumps may be used in one or two ormore stages. In the present specification such primary pump or pumpswill always be known as the backing pump.

In both forms of the condensation pumps referred to herein. there is anexternal envelope ordinarily circular in cross section, with a body 10which terminates in an enlarged bottmn section 11, in which a suitableliquid of low vapor tension is deposited and contained while in theliquid state. A small seal-oil tube 9 is provided on one side of thebottom section 11 to provide the means for cleaning the pump or changingthe liquid used.

Adjacent to the top of the body 10 is a projecting elbow 12 integralwith or secured to body 10. Said elbow has a beaded or col lar section13 adjacent the end of the bent section thereof. Said elbow continuesinto the form of a tubular portion 14 of relatively large cross sectionand to which some form of tube is connected by a vacuum-tight joint,dependent upon the material used, such tube leading to the vessel whichis to be exhausted. Such connective member is not shown but eX- tends tothe vessel under exhaustion and which is being degassed, which vesselalso is not shown in the drawing.

The upper section of the body 10 is constricted at 18 to provide section19 of smaller diameter than body 10 and having three nipples, one (20)adjacent to the body 10. another (21) projecting vertically upright atone side of said section 19, and a third (22) intermediate the other two(20 and 21). Tubes 20 and 22 are designed to be connected to a watersupply system for cooling the condensation pump in a manner to bedescribed later. Tube 2i serves to connect this condensation pump withthe backing pump already referred to.

Within the body 10. there is'inserted beneath the elbow 12 an internaltubular envelope 23 arranged concentrically with the wall of body 10.but away therefrom. The lower end of said internal envelope isconstricted and bent to form a U shaped tube 24. Said U-shaped tubeserves not only as a dis charge tube for condensed liquid through thespout 25. which is turned upwardly, but also a liquid seal to preventthe vapor arising from the boiling liquid in the lower part of thechamber 11 from passing upwardly into the internalenvelope 23 throughthe opening 25. Internal envelope 23 is held in position by suitablypositioned spacer members 26, one only of which is shown.

Depending into the mouth of said internal envelope 23 and concentricwith it is a short cylindrical member 27, with an upper funnelshapedsection 29 coinciding with and sealed to the wall of the externalenvelope 10. This cylindrical member serves as a deflecting collar forthe vapor as it rises from the boiling liquid in the bottom of section11, said vapor being deflected downward through the annular passage 30between the external wall of member 27 and the internal wall of member23. v

Concentrically arranged with the external envelope 10, the internalenvelope 23, and the deflecting collar 27, and inside all of them 7 is awater-cooled condensing element 31 which comprises a unit having anexternal wall 32 which wall is generally cylindrical and which formswith the internal'wall of deflecting collar 27 a passage 33 of annularconfiguration therebetween.

Said cooling member 31 at its top 34 has its external wall flared andsealed to the material of the external envelope 10 at the constrictedsection 18. There is also provided at the lower end of said member, 31an extension of wall 32 which is inwardly turned to meet an inside wall35 so as to form with said inside wall 35 an annular chamber ofirregular configuration which extends up-' wardly in theshape of anarrow tube-like open section or passage 36 elbowed at 37' and 38.

Said passage 36 extends through the condensing element 31 from the openbottom of the element to the top thereof, the passage terminating atthelower end of the nipple 21 to which the material of the internal wall 35of said condenser member 31 is joined so that there may be a flow of gasupwardly through the condensation pump being described to the backingpump, not shown, but suitably connected to said nipple 21.

Depending'into said condenser member 31 is an elbowed tubular member.39, the upper end 40 of which is sealed to nipple 22. The lower end 41of said tube 39 is open to provide for the discharge of a cooling mediuminto the condenser 31, such cooling medium being admitted through nipple22.

By sealing the tube 39 and the internal wall 35 of the condenser memberto the external envelope 10 at the points where nipples 22 and 21 arerespectively joined to said external envelope the chamber 19 iscompleted, and is sealed off from the remainder of the pump. -It isevident, therefore, that condenser member 31 through-its inlet nipple22, its outlet nipple 20, and its general construction furnishes themeans of conducting into and out of the center of the condensation pumpa body of cooling water or other medium which may be kept in continuousmotion so that the outer walls of the member 31 may always besuificiently cooler than the vapor passing around it to condense thelatter and thus assist in the operation of the pump.

Briefly stated the operation of the pump is as follows: Mercury or anyother suitable liquid of low vapor tension is deposited in the lowersection 11 of external envelope 10 and the proper stream of water orother cooling medium is started through the condenser 31. A vacuum-tightjoint has already been made between the vessel to be exhausted, notshown, and the elbowed section 12 and a connection'made with the backingpump at nipple 21.

When the backing pump has provided in the system a reduced pressure(this may be as high as .2 or .3 or as low, say, as .03 millimeter ofmercury), the source of heat for vaporizing the liquid, either anelectrical heater or any other suitable source, may be started.

Under the reduced pressure produced and maintained by the backingpump'in the system, this liquid will boil easily and its vapor will soonrise within the external envelope 10 and will be deflected by thedeflecting collar 27 so as to shoot downward with high velocity throughthe annular space 30 between collar 27 and the internal envelope 23. Theparticles of this vapor mingle with the air or other gas in and belowthe annular space 30 and bombard the molecules of such gas, acceleratingtheir movement downward into the lower part of internal envelope 23where'they are caught by the sucking action of the backing pump andeliminated through passage 36 and nipple 21.

At the same time, the vaporxcomes in contact withthe condenser 31, andcondenses on' the cool walls thereof and drops down out of the waythrough discharge neck 24 and outlet 25. The high velocity of this vaporas it passes down the annular space 30 causes a reduced pressure in itswake and thus hastens the movement of air or gas from the vessel'beingexhausted, bringing the vacuum in such vessel down to a very low pointin an incredibly short time.

In the form of they invention shown in Figure 2, called a two-stagecondensation pump, the structure is identical with that shown in Figure1, except in respect to the internal envelope 23 which provides the mainpassage for vapor about the cooling member 31. Each of the parts foundin Figure 2, which also appear in Figure 1, are given the same ordinalas in Figure 1, except that 100 has been added thereto.

Referring now to the changes in the internal envelope 23 in order tomake the condensation pump a two-stage pump, it will be noticed inFigure 2 that the lower section of member 123 retains the U-tube 12 iand the discharge opening 125 except that both are disposed at the siderather than in the center of member 123. In addition, however, thebottom of member 123 is provided with an opening 150 which may be formedby the inturning of material 151 or by adding an inverted funnel-shapedsection sealed to the lower edge of the opening 150 and projectingupwardly a short distance into passage 136 leading to nipple 121 and thebackingpump, not shown. Said section 151 has a cylindrical top sectionterminating in aperture 152, said cylindrical section beginning at point153. Between section 151 and the condensing elements is a passage 154i.

Therefore, in the operation of a two-stage condensation pump, asillustrated, the vapor formed in the reservoir 111 not only passes upbetween the internal envelope 123 and external envelope so as to strikethe deflecting collar 27 to be projected into the 111-- ternal envelopefrom above, but also rises rapidly from the body of the liquid insection 111 and shoots through the opening 150 into passage 136. Indoing so, it not only accelerates the particles of air or gas beingconveyed up passage 136 by the suction ot the backing pump butmaterially assists the backing pump in providing a reduced pressure todraw other particles of air or gas which have been accelerated towardthe bottom of internal envelope 123 through the annular space 130.

It will be seen that these two sources of bombardment can neverinterfere with each other because of orifice 152 extending up into tube136. Therefore, this new passage provided a second stage in theproduction oi the vacuum and thereby increases the chicieney of the pumpaction. Of course, as the vapor of the volatile liquid passes up tube136 it meets the internal walls of cooling member 131, condenses onthese walls, and passes down them to drop back into chamber 111 throughiJ-tube 124, and opening 125 without interfering with the stream ofvapor and air particles going up tube 136.

I claim:

1. In a condensation pump comprising an internal cooling system whollywithin the other sections of the pump, an external envelope adapted totelescope over said cooling system from below, and a deflecting collarsealed to said external envelope and adjacent said cooling systemintermediate its length for directing rapidly moving vapor into the pathof air or gas coming from the vessel to be exhausted.

2. In a condensation pump, an external envelope, a deflecting collarattached to said envelope, an internal envelope concentric with saidexternal envelope and said deflecting collar and so arranged that vapormay flow forwardly only in a path therebetween, an internal condensertelescoping into said envelopes, said deflecting collar being arrangedto change the direction of the flow of the vapor through one hundred andeighty degrees, and means for causing molecules of air and from thevessel to be exhausted to join with said vapor and travel therewithalong said condenser.

3. A condensation pump comprising an external envelope, an internalenvelope suspended therein and spaced from said external envelope, saidinternal envelope terminating in a gooseneck spout to dischargecondensed vapor, a condenser concentric with and within said innerenvelope, there being a gas passage within said condenser comprising anexit tube for said pump, and a deflecting collar dividing said externalenvelope into sections and having a skirt extending between said.condenser and said internal envelope to reverse the direction of theflow of vapor in said pump and to direct the vapor downwardly about saidcondenser.

A condensation pump comprising an external envelope, an internalenvelope suspem'led therein and spaced from said external envelope, saidinternal envelope terminating in. a gooseneck spout to dischargecondensed vapor, a condenser concentric with and within said internalenvelope, there being a gas passage within said condenser forming anexit tube for said pump, means for causing the vapor to flow downwardlyabout said condenser, and means for causing a cooling media to flowupwardly from the bottom of saidcondenser.

A condensation pump comprising an external envelope, an internalenvelope suspended therein and spaced from said external envelope, saidinternal envelope having a tubular passage vertically therethrough andterminating in a gooseneck spout to dis- -'.:harge condensed vapor, acondenser concentric with and within said envelopes, there being a gaspassage within said condenser to provide an exhaust air or gas conduitthrough said pump, and a deflecting collar dividing saidexternalcnvelope into sections and having a skirt extending between saidcondenser and said inner envelope, said collar reversing the flow ofvapor in said pump and causing the downwardly flowing vapo to surroundsaid condenser.

6. A condensation pump comprising an outer envelope providing agenerating chamber, an internal envelope, and a deflecting collar, saidenvelopes and collar being colicentrically arranged and said de lectingcollar being sealed at the periphery of its upper end to said external.envelope, said envelopes and collar being so disposed that mercury orother vapor rising from said generating chamber is in contact with andrestrained by said external envelope until it strikes said deflectingcollar, the vapor being turned thereby so as to take a parallel butdiametrieally, opposite direction without interference with the Originalstream of vapor particles.

7. In a condensation pump, an external envelope providing a generatingchamber, an internal envelope, and a deflecting collar attached to saidexternal envelope at its upper end and extending downwardly into saidinternal envelope, said collar being in annular form with walls parallelto said external envelope, said envelopes and collar being so disposedas to cause a reversal in the flow of the vapor in parallel streams, theupper end of said internal envelope forming with the deflecting collaran annular aperturethrough which the rapidly moving stream of vaporparticles is projected downward by means of its impingement againstsaiddeflecting collar.

8. In a condensation pump, an external envelope providing a generatingchamber, a deflecting collar, and an internal envelope suspended betweensaid external envelope and said deflecting collar, said internalenvelope terminating at its lower end in a gooseneck spout which servesto discharge condensed vapor into said genera-ting chamber and at thesame time preventing vapor rising from said generating chamber fromescaping from said outer envelope except through an annular passagebetween said external and internal envelopes.

9. A condensation pump having an intake tube and comprising an externalen her,

velope providing a generating chamber at its lower end and having achamber at its upper end into which said intake tube empties, adeflecting collar, an internal envelope having at its lower end a.goose-necked tube, and a condenser having a passageway therethrough toprovide an exhaust exit for air or gas from said pump, said envelopes,collar and condenser being concentrically disposed, there being anannular passage between said defleeting collar and said condenserproviding means of communication with said chamber in the upper part ofsaid external envelope and in turn with the intake tube, so that air isdrawn into said pump by the suction produced by a downward rush of vaporfrom said deflecting collar, such air commingling with the vapor to becarried to the lower extremity of said condenser where it is removed bysuction produced by a backing pump, the vapor in said pump beingcondensed on the walls of the condenser on its way downand dropping intothe lower porv tion of the internal envelope to be conveyed through saidgoose ncck shaped tube to the generating chamber.

10. A condensation pump comprising an outer envelope forming agenerating chama deflecting collar thereon, an inner envelope concentricwith said outer envelope and said collar, and a cooling chamber in whicha cooling medium is constantly circulating and through which there is acentral passageway, and in which vapor from said generating chamberrises vertically in said outer envelope to said deflecting collar, isturned through 180 degrees by the latter, shoots with high velocitydownward through an annular space between said deflecting collar andsaid internal envelope, and by virtue of the high velocity drags with itair from the vessel to be exhausted, the vapor at the same time comingin Contact with said cooling chamber in which water is continuouslycirculating, condensing on the walls thereof and dropping out of theway, leaving the air particles to be caught by a suction produced by abacking pump and carried vertically upward through the passage in thecenter of said condenser, the passage in the center of said condenserproviding an exhaust exit for air or gas from said pump.

11. In a condensation pump, an external envelope, a backing pump inconnection therewith, and a deflecting collar attached to said externalenvelope and so disposed in the path of heated vapor in said envelope asto change the direction of flow of said heated vapor through 180 degreeswithout develop ing a back pressure, said vapor being thus turned withhigh velocity toward the bot tom of the envelope and into the path ofthe suction of said backing pump.

12. A condensation pump of a twostage type, and comprising an outerenvelope forming a generating chamber, a deflecting collar in. saidenvelope, an internal envelope the upper section of which is concentricwith said outer envelope and said collar, said inner envelope extendingabove and outside the lower rim of said collar and having a funnel-likeopening through the cent-er thereof and a goose-neck drip tube from thelower end thereof, and a condenser circular in configuration and havinga central passage therethrough to provide an exit tube for exhaust airor gas and telescoping into said collar and said inner envelope fromabove, said condenser being'concentrically arranged within saidenvelopes and said collar, such vapor being adapted to flow through thecenter of said inner envelope and on the exterior thereof to becondensed on the outer or inner wall of said condenser, the condensedvapor flowing back into the generating chamber by wlay of saidgoose-neck tube, the funnel-like tube of said internal envelope beingalongside of but separated from said gooseneck tube and being disposedto admit and direct a portion of the vapor rising from said generatmgchamber directly into the exhaust tube in the center of said condenser,such vaporforming an independent source of bombard ment of the air andgas as a second stage in the operation of said pump.

13. In a condensation pump, an external envelope, an internal condenserhaving a passageway therethrough, and a deflecting collar attached tosaid external envelope and so disposed in the path of the heated vaporas to change the direction of such heated vapor through one hundredeighty degrees without developing a back pressure and to spread suchvapor into a thin film moving toward the bottom of the pump around saidcondenser and into the path of the suction of a backing pump through thepassageway in said condenser and thence upward through the passageway insaid condenser.

14. A condensation pump comprising an external envelope, an internalenvelope suspended therein and spaced from said external envelope, saidinternal envelope terminating in a gooseneck spout to dischargecondensed vapor, a condenser concentric with and within said envelopes,there being a gas passage within said condenser to provide an exhaustair or gas conduit through said pump, and a deflecting collar dividingsaid external envelope into sections and having a skirt ex tendingbetween said condenser and said inner envelope, said collar reversingthe flow of vapor in said pump and causing the downwardly flowing vaporto surround said con-- denser.

CHARLES T. KNIPP.

